Futurist Christopher Barnatt is the author of two 3D printing books, and is well known in the 3D printing community. His latest book -- "The Next Big Thing: From 3D Printing to Mining the Moon" -- covers far more than additive manufacturing. But as "3D Printing" is in the sub-title, we thought we'd ask him what it is all about.

3Ders: "The Next Big Thing" is a very broad title, so can you tell us what the book covers?

Chris: Well, the idea is to highlight four future technological revolutions that will change the world in the same way that the Internet has transformed our lives in the past few decades. In fact, one of the central messages is that we need to recognize how the Internet Revolution is over in order to move on and embrace those revolutions ahead.

3Ders: One of which is 3D printing, right?

Chris: Yes and no! One of the book's 10 chapters is on 3D printing, and it keeps coming up in almost every other chapter. But, looking 20 or 30 years out, I think that 3D printing will form part of a broader revolution in 'local digital manufacturing' or 'LDM'. LDM is the fabrication of physical things from digital designs in almost any location, and certainly today 3D printing is the technology that is taking us in this direction. But there are other technologies in development that can turn a digital design into a physical thing, and most notably synthetic biology and nanotechnology. I therefore predict that it will be the convergence of 3D printing with synthetic biology and self-assembly nanotechnology that will be the Next Big Thing to transform manufacturing.

3Ders: But why do you think this? Why will 3D printing itself not create the next manufacturing revolution?

Chris: 3D printing is a set of technologies that is developing very rapidly on both a consumer and an industrial scale. Even so, there will always be limitations to building objects in layers. Not least, it will be difficult to radically speed up layer-based additive manufacturing methods, especially if we want to digitally fabricate highly complex products with very high levels of detail.

3Ders: So how may synthetic biology and nanotechnology help out?

Chris: Well, synthetic biology uses engineering principles to design and construct living things. Rather than building objects in layers from CAD files or scans, it uses the digital code stored in DNA to fabricate things using 'natural' self-assembly methods. By writing custom DNA using open source apps like GenoCAD, synthetic biology pioneers are starting to construct living things that have never existed in nature. These may be future products themselves, or else micro-organisms, plants or animals that will work as a kind of living manufacturing technology. Already synthetic yeast and synthetic bacteria have been engineered that can ferment sugar beet, algae or other feedstocks into bioplastics, biofuels and pharmaceuticals. Synthetic biologists have already also created biological transistors -- or 'transcriptors' -- that may allow the future fabrication of bioelectronic devices.

3Ders: And nanotechnology?

Chris: Well, for decades we have been perfecting top-down methods -- like 'nanolithography' -- that allow Intel and others to make microprocessors that feature billions of tiny transistors. But there is a second phase of nanotechnology on the horizon -- Nanotechnology 2.0 if you like -- that will self-assemble products on the molecular scale, again based on a digital design. For example, developments in protein engineering are allowing the creation of 'foldamers' -- special polymers with pre-programmed shapes that can lock together like specialist Lego blocks when mixed.

Just imagine having all of the molecules needed to make a smartphone, and putting them in a cocktail shaker, giving it a really good workout, and then opening it up to take out a fully assembled Apple or Samsung device. It sounds crazy, but this is the promise of molecular self-assembly -- and scientists have already started to use such self-assembly methods to make synthetic DNA and even synthetic viruses. As reported on 3Ders earlier this year, a team led by Martin D. Burke at the University of Illinois have even built the first 'molecule making device' based on self-assembly methods.

3Ders: And how will this align with the future of 3D printing?

Chris: Today, we can already see the convergence of 3D printing, synthetic biology and molecular self-assembly by looking to the field of bioprinting. Here, pioneers like Organovo have developed 3D printers that lay down layers of living cells. For example, Organovo are now bioprinting their exVive3DTM Human Liver Tissue for use in drug testing.

One of the really cool things about Organovo's bioprinting method is that they do not print individual cells. Rather, their print head positions 'bio-ink spheroids' that each contain tens of thousands of cells, with the different cells needed to make the tissue under construction all mixed together in an aggregate. However, once printout has taken place, the cells in the aggregate re-arrange. For example, a blood vessel may be bioprinted from bio-ink spheroids that are an aggregate of primary endothelial cells, smooth muscle cells and fibroblasts. After printout, the primary endothelial cells migrate to form the inner lining of the bioprinted blood vessel, while the smooth muscle cells travel to the middle, and the fibroblasts position themselves to constitute the blood vessel's outer tissue. What this means is that Organovo's bioprinting process already relies on the ability of living cells to self-assemble into appropriate structures in a post-printout 'maturation' phase. Bioprinting is therefore already a digital manufacturing process that is based in part on layer-based fabrication, and in part on biological self-assembly.

3Ders: Wow, that is really interesting -- and probably presents a great many opportunities for future development.

Chris: Exactly. Today, bioprinting research is focused on the fabrication of living human tissue for drug testing and future human transplantation. But there is the related possibility of creating bioprinters that will output living materials engineered by synthetic biologists, and that will self-assemble into their final, programmed form after 3D printout and then die on digital cue. For centuries we have made things from organic materials -- such as wood and leather -- that were once alive, but which we use in a dead state. But in the future, we may digitally fabricate all manner of products from synthetic organic materials that remain alive throughout a production (3D printing) and post-production (maturation self-assembly) process. 3D printing will give us the basic form of the objects we want to locally manufacture. But synthetically-programmed organic processes will get on with sorting out the detail.

3Ders: It sounds like a great deal of computer processing power will be required to work all of this out.

Chris: An amazing amount! But we are developing that. Indeed -- as I explain in the book -- we are fast developing AI systems that will allow future forms of local digital manufacturing to become a reality. And in time self-assembly methods will not just be limited to making things from organic materials. Today, we move around information using nanoscale and microscale hardware called 'microprocessors'. But in 20 or 30 years, I think we will use 'microfabricators' based on microscale and nanoscale technologies to locally digitally manufacture a wide range of products from individual molecules and maybe even individual atoms.

3Ders: If brief, what else do you cover in the book?

Chris: Well, aside from looking at future revolutions in local digital manufacturing and AI, I also focus on obtaining resources from space, as well as using local digital manufacturing developments to upgrade ourselves into 'transhumans'. Though to be honest, everything really is linked together. For example, one way to obtain resources from space may be to build solar power satellites that will beam energy down to the Earth by microwave -- something that the Japanese Space eXploration Agency (JAXA) is actually working on. And a space solar power scientist called John Mankins has now developed a design for a solar power satellite that would self-assemble from a swarm of smaller components, and many of these may one day be 3D printed in space.

NASA and the European Space Agency are also already investigating the possibility of 3D printing lunar or Martian bases. To venture into space in search of more resources, the human race is also likely to require a bit of transhuman upgrading, and this could involve the use of bioprinting, genetic engineeering, cybernetics and AI to turn at least some of us into a space-faring species. So you see, everything in The Next Big Thing is a kind of future technological soup.

3Ders: It sounds like your new book may make people's heads spin!

Chris: I certainly hope that it will provoke thinking and debate -- especially amongst Makers. Today many advocates of 3D printing recognize that we are on the verge of a manufacturing revolution -- and "The Next Big Thing" very much places the present and future of 3D printing in the context of a whole host of other exciting and sometimes frightening innovations.